<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>js01</title>
		<script type="text/javascript">
			document.write("js学习第一课</br>");
			function alertMessage(){
				alert("页中引入（body标签内）");
			}
		</script>
	</head>
	<body>
		<script type="text/javascript">
			document.write("JavaScript在HTML的引用共有4种：");
		</script>
		<input type="button" onclick="alert('页头引入（head标签内）')" value="1" />
		<input type="button" onclick="alertMessage()" value="2" />
		<input type="button" onclick="alertMessage2()" value="3" />
		<script src="../js/01.js" type="text/javascript"></script>
		<br />
		4.引入外部JS文件；
		<hr />
		<a href="02.html">下一课</a>
	</body>
</html>
